| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a lighting circuit for a discharge lamp capable of maintaining lighting of the discharge lamp, even if power generation amount becomes lower than rated power, without lowering rated power of the discharge lamp for a headlamp. <P>SOLUTION: This lighting circuit 16 for the discharge lamp is provided with a power monitoring circuit 26 for detecting a driving circuit supply power value DV supplied from a power generator 12 for a vehicle, a reference value arithmetic circuit 28 for outputting a rated power value SV as a reference power value BV when the driving circuit supply power value DV is a rated power value SV of the discharge lamp 18 or more and outputting the reference power value BV which is equal to the driving circuit supply power value DV or lower than the driving circuit supply power value DV when the driving circuit supply power value DV is lower than the rated power value SV, and a differential output device 30 for comparing the reference power value BV with a discharge lamp supply power value IV supplied from a constant power supply circuit 32 to the discharge lamp 18 and outputting a power reduction signal RS or a power increase signal IS to the constant power supply circuit 32. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
